Imagine that one day, out of the blue, people begin falling ill. The illness starts with simple flu symptoms but, in some people, rapidly progresses to death. In those unlucky victims, the disease causes the lungs to fill with fluid, in a few days for some, in only hours for others. In one autumn month of 1918, in Philadelphia, nearly 11,000 people die. In one day, 759 deaths occur. To add to the horror, rather than preying on the elderly and children, this disease seems to kill the healthy young and middle aged. The disease spreads rapidly, reaching the most remote outposts imaginable. In a small Eskimo village in Alaska, for example, adults begin coughing on Monday and, three weeks later, 72 of the 80 adult villagers are dead, leaving behind 46 orphaned children. Doctors, hospitals and morgues all over the country are overwhelmed. Cities close theatres, restaurants, churches and, in fact, any place where people are wont to gather. No one knows the cause of the disease or how to end it. Even the military draft is suspended, amid World War I. Doctors try desperate measures, concocting crude vaccinations consisting of the blood and mucus of the sick in an attempt to inoculate patients. And then, as quickly as it started, the disease is over. It vanishes, leaving a stunned population behind, struggling to forget the horror of both war and pestilence.

Gina Kolata's new book, Flu: The Story of the Great Influenza Pandemic of 1918 and the Search for the Virus That Caused It, vividly describes how this calamity, the most deadly pandemic our country has ever faced, affected society. It offers not only an apocalyptic vision of the course of the disease, but also details the ongoing efforts to track down its source. The quest to understand the unparalleled virulence of the 1918 influenza strain has motivated dedicated researchers for decades. With the advent of techniques unimagined in 1918, researchers have now begun to get a handle on the 1918 flu.

Kolata tells how an American military pathologist used a massive warehouse of tissue samples to find fragments of the 1918 virus that had been preserved in paraffin blocks. Using the polymerase chain reaction (PCR) process to amplify the small scattered fragments of virus in lung tissue samples, researchers have the opportunity to unlock the secrets of this illness. The author draws a wonderful picture of two expeditions whose goal was to gather additional lung tissue samples from bodies buried in 1918 in permafrost. One expedition was mounted on the spur of the moment by a retired pathologist and cost about $4,000. The other was a massive expedition, taking years to plan and execute, that moved in the glare of publicity covered by the world's media, and cost at least half a million dollars. Guess which one found the virus.

In addition, Kolata explores the intimate relationship between pigs, fowl, humans and the influenza virus. She describes the intense search for the source of a new and deadly strain of flu that killed a young child in Hong Kong in 1997. Luckily, that turned out not to be the index case of the next influenza pandemic.

The book taps into the general concern of epidemiologists—that people may once again start dying from a new and lethal strain of influenza—a fear that surfaced when political, legal, economic and medical agendas collided some 20 years ago to create the infamous swine flu debacle, which was motivated by fear of a repeat of the 1918 pandemic.

Flu is a great read, although following the machinations of the swine flu episode can be slow. This subject touches a chord in us today, when we are no longer quite so confident of our ability to outwit disease as we were in the days before Ebola, antibiotic-resistant Staphylococcus species and reports of horrific diseases concocted in the Soviet Union's massive biological weapons programs (diseases that some believe are being replicated in other laboratories throughout the world).

My only complaint about this book is that it was written just a little too soon. We become fascinated by the medical detective work, but the book ends before the culprit is really identified. At the final page, researchers are still working hard to determine what it was about the 1918 influenza virus that made it so deadly, but they don't yet have any real answers. The book concludes on a frustrating note.

Next fall, you may want to put this volume in the waiting room of your office practice. Compliance with influenza vaccination might improve markedly.